Cylindrical Screen

cylindrical screen is a coarse screening device in a waste paper pulping production line, typically installed after a high-consistency hydrapulper. Its core function is to screen the pulped waste paper, separating large and heavy impurities (such as plastic flakes, foam, stones, etc.) to recover valuable fibers and protect subsequent fine screening equipment.

What are the uses of a cylindrical screen?

The main body of a cylindrical screen is a horizontal rotating cylinder made of screen mesh (screen drum), with spiral guide vanes usually installed on the inner wall. Its working principle can be summarized as rotational separation and hydraulic washing:

Screening Separation: Waste paper pulp enters the rotating screen cylinder from one end. Under the action of centrifugal force and gravity, the good pulp (fiber and water) with a diameter smaller than the screen openings is thrown out or filtered out and collected in the pulp tank below for recycling.

Impurity Conveying: As the screen cylinder rotates, the spiral blades on its inner wall continuously propel various impurities (such as plastic sheets, fabrics, heavy slag, etc.) that cannot pass through the screen openings forward.

Washing and Discharge: During the impurity conveying process, a spray pipe above the equipment continuously sprays water to wash away useful fibers adhering to the surface of the impurities, ensuring that the fibers are fully recovered. Finally, the cleaned impurities are discharged from the other end of the screen cylinder.

Coarse Screening: As the first screening process after pulping, it removes large impurities, effectively reducing the burden and wear on subsequent fine screening equipment (such as pressure screens), ensuring the stable operation of the production line.

Fiber Recovery: Specifically designed for recovering usable fibers that have not been completely dispersed or are mixed with impurities from the high-concentration slurry discharged from the hydrapulper, improving raw material utilization.

Special Material Handling: For example, patented cylindrical screens are specifically designed for processing composite packaging materials such as milk cartons, performing slurry washing and aluminum-plastic separation and conveying after crushing.

What are the advantages of cylindrical screens?

Compared to other screening equipment, the cylindrical screen has significant advantages in the roughing stage:

High processing capacity and less prone to clogging: Due to its open structure and continuous spray washing, the cylindrical screen can quickly accept and process slurry containing a large amount of impurities, minimizing the risk of clogging or overflow.

Combined conveying function: Through its internal spiral blades, the cylindrical screen simultaneously screens and conveys impurities, achieving "multi-functionality" and simplifying the process.

Simple structure and easy maintenance: The overall structural design is relatively simple, with few moving parts, making daily maintenance and repair convenient and ensuring high operational reliability.

High fiber recovery rate: Through rotational tumbling and powerful spray washing, the good slurry carried by impurities is fully washed out, effectively reducing fiber waste.